The Birth Interval and the Odds of a Male Birth in Sub-Saharan Africa: Implications for the Sex-Ratio

Open Access
Morse, Anne Roback
Graduate Program:
Master of Arts
Document Type:
Master Thesis
Date of Defense:
September 15, 2017
Committee Members:
  • Jennifer Van Hook, Thesis Advisor
  • Nancy Luke, Committee Member
  • Marianne M. Hillemeier, Committee Member
  • Fetal loss
  • Sex ratio at birth
  • sub-Saharan Africa
  • Miscarriage
  • Spontaneous abortion
Many studies seek to understand the social and biological determinants of the sex ratio at birth, but the literature has neglected to explore how rates of fetal loss might affect a population’s sex ratio at birth due to a difficulty in measuring early fetal loss at a population level. Fetal loss is important for understanding sex ratios at birth because it occurs more often for male than female fetuses (Pelletier 1998; Caselli et al. 2006; Kraemer 2000, Carlo di Renzo et al. 2007; Byrne and Warburton 1987), and poor maternal wellbeing is linked to higher levels of fetal loss (Kim et al. 2012; Nepomnaschy et al. 2006; Agarwal et al. 1998; Norsker et al. 2012). To address this gap in the literature, I use birth intervals as a proxy of fetal loss after controlling for other determinants of birth intervals such as contraceptive use. Using data from the Demographic and Health Surveys (DHS) in sub-Saharan Africa (SSA), I find a negative relationship between the length of birth interval and the odds of a male birth. I suggest that this relationship can be explained by repeated early fetal loss which both decreases the odds of a male birth and lengthens the birth interval.